1. Field of the Invention
The present invention generally relates to an external wall for a building. More specifically, this invention is directed to an improved support panel to secure external wall forming members such as brick, tiles or stones to complete an external wall assembly for a building.
2. Description of the Related Art
Brick walls have been used for centuries as a premium building material due to their strength, beauty, and durability. Unfortunately, brick walls are typically laid brick-by-brick, which tends to be time consuming, labor intensive, and therefore expensive. Thin brick veneer was developed as a means for achieving the beauty and durability of brick walls without the associated expense.
Thin brick veneer is produced using a variety of manufacturing methods including thin bed set, thick bed set and prefabrication in cast molds. Thin brick panels can be premanufactured or can be assembled to a wall of a building on-site. Thin brick panels generally include a substratum, such as steel, aluminum, plywood, asphalt-impregnated fiber board, cementitious board, polyurethane, and polystyrene foam board. With the on-site assembly method, the substratum is fastened to the exterior wall of a building and an array of thin bricks are applied to the substratum, typically with an adhesive. Then mortar, or grout, is applied between the thin bricks to obtain a permanent brick veneer wall assembly.
The prior art has suggested a variety of thin brick panel constructions. For example, U.S. Pat. No. 2,924,963 to Taylor et al. teaches a method for attaching a clay veneer brick to pre-existing buildings. Taylor et al. disclose a brick unit, a wall clip, and mortar. The brick unit includes a back side, a face section, and longitudinal ribs along the top and bottom. The longitudinal ribs are beveled at a front side at a 45 degree angle. The clip is made from sheet metal and is made to resiliently receive the brick unit. The clip includes a flat upstanding lug and a bent tail lug, both of which have fastener holes punched therethrough. Extending perpendicularly from the clip are a plurality of resilient clamping members, each having a downturned lip to resiliently receive a respective longitudinal rib of a respective brick unit. The downturned lip also has an upturned flange, which, when the clip is fitted to the veneer brick, rides against the longitudinal rib of the brick unit, causing the downturned lip to deflect and resiliently retain the brick unit.
Unfortunately the clip of Taylor et al., is unnecessarily complex with many detailed bends. Moreover, an overabundance of individual clips must be handled and secured to a building just to construct a single wall, which is inefficient, labor intensive, and costly. Finally, great amounts of care and time must be given to the precise positioning of each clip to ensure that each brick is squarely aligned with respect to the other bricks.
U.S. Pat. No. 2,087,931 to Wallace et al. teaches a means for attaching bricks to a wall such that each brick is individually supported so that its position in the wall is not dependent upon the other bricks. Specifically, Wallace et al. disclose wall sheeting having a plurality of spaced apart strap members secured thereto by nails. A plurality of support clips are riveted to the strap members at regularly spaced intervals. The support clips have extending portions that are bent outwardly to form arms with inwardly bent terminals for engagement with surfaces of the bricks. The natural resiliency of the clip so constructed forces the terminals into engagement with the brick surfaces. The terminals are angularly disposed relative to the adjacent surfaces of the brick such that a sharp edge of the terminals engage the brick thereby materially increasing the tenacity of the holding action.
The Wallace et al. disclosure relies on a plurality of strap members and a plurality of support clips for applying bricks to a wall. Manufacturing all the components required for the Wallace et al. disclosure and the process of assembling the components to a wall unnecessarily incur additional labor and material cost. Furthermore, Wallace et al. do not teach a means for accommodating oversized and undersized bricks.
U.S. Pat. No. 6,098,363 to Yaguchi teaches a support panel for supporting external wall forming members, or bricks. The bricks are of rectangular parallelpiped shape, meaning they have oppositely parallel surfaces all over. The bricks each have a main surface, a rear surface, side surfaces, and end surfaces. The side surfaces include elongated upper and lower lateral extensions that define flat ledges or minor surfaces that are parallel with the main surface. The support panel includes a flat back plate and is stamped from stainless metal sheet to form parallel rows of C-shaped upper and lower engaging members terminating in respective upper and lower securing fingers. The distance between the upper and lower engaging members is substantially identical to the width of a respective brick. A brick is inserted between the upper and lower engaging members. This insertion pushes the upper lateral extension of the brick into a space defined by the upper engaging member and upper securing finger thereby causing the upper engaging member to elastically deform while the lower lateral extension of the brick is urged flat against the back plate of the support panel within the lower engaging member. As a result, the brick is clamped between the upper and lower engaging members and by the bent securing fingers.
In an alternative embodiment, each brick only has an upper lateral extension and an oppositely disposed flat side surface. Respectively, the support panel includes only rows of upper engaging members and securing fingers. Each upper engaging member has an outer, top surface and an inner bottom surface. As before, the upper lateral extension of each brick is pushed into the space defined by the respective upper engaging members such that the upper lateral extension of the brick engages the inner bottom surface of the respective upper engaging member. Simultaneously, the brick is pushed toward the back plate of the support panel until the flat side surface locates against the top surface of the respective engaging member below. Thus, the brick becomes pinched between the upper engaging member and the top of an upper engaging member from the row of upper engaging members below the brick.
In both of the Yaguchi embodiments, however, the support panel clamps on oppositely disposed parallel surfaces of the brick. This is detrimental because the size of the bricks varies significantly compared to the stamping tolerances attainable with the support panel. In other words, either one of two undesirable conditions must occur. The bricks must be held to an extremely close width tolerance to accommodate reliable and repeatable snap fit insertion to the support panel. This is extremely costly, if at all possible, on a mass production basis. Or, each brick must be oversize with respect to the distance between the rows of engaging members to ensure firm clamping of each brick. Oversize bricks will fit fine in the first row of engaging members, but will start to interfere when they are assembled to adjacent rows of engaging members because the engaging members will be filled with bricks and have no room to deflect. Alternatively, if the bricks are undersize, they will fit loosely within the engaging members thereby leading to problems. When the mortar gets applied, loose bricks will shift due to the slack and hairline cracks in the mortar may result.
From the above, it can be appreciated that thin brick panel assemblies of the prior art are not cost effectively optimized to accommodate typical brick tolerances, simplify assembly, and thus lower costs. Therefore, what is needed is a combination of a thin brick veneer assembly that incorporates novel and simple retaining features in a substratum or support panel and related features in a brick to advance the art of veneer brick assembly.